Use of Chromium(III) to Enhance the Protonation of Biomolecules by Mass Spectrometry

University Of Alabama Tuscaloosa, Tuscaloosa AL

Investigators

Abstract

The Chemical Measurement and Imaging program of the Division of Chemistry supports the research of Professors Carolyn Cassady, David Dixon, and John Vincent from the University of Alabama. Their project improves the sensitivity of mass spectrometry (MS), which is a common analytical tool for identifying and characterizing chemical substances. The researchers use experimental and computational approaches to optimize MS conditions. This project specifically improves MS analysis of peptides. Peptides are used in the study of protein structure and function. The ability to better identify and characterize peptides has benefits for basic molecular biology research, drug development, human health, and biotechnology. Students working on this project receive mentoring and training in an interdisciplinary, collaborative research environment. This research project improves the sensitivity of mass spectrometry (MS), an important means of characterizing biomolecules. Specifically, the researchers are probing the use of trivalent chromium, Cr(III), to enhance the intensity of the protonated ion signal obtained during the analysis of peptides and other organic molecules. This work includes optimization of experimental MS parameters and determination of the most suitable reagents for inducing proton transfer. Both metal salts and organometallic complexes are studied. The fundamental mechanism of the enhanced protonation process is also being explored. High level electronic structure calculations are used to elucidate the enhanced protonation mechanism with Cr(III) and to determine the locations of the added protons on the organic molecule. This novel Cr(III) method benefits proteomic researchers who use MS to identify peptides in protein digests. The ability to better identify and characterize peptides increases our understanding of biological processes and leads to the development of new pharmaceutical drugs to target specific metabolic pathways.